[Radiance-general] rendering large space with small detail

[Evangelos Christakou]

Hi,
Thinking about the difference between photorealism rendering and light
visualization related in RWR chapter 1, pag 4 and 5. I'd like to
elucidate some questions about this topic:
Doing so, ( procedures included below by example), is still a
phisically based simulation?
Is it a valid procedure to predict how natural light behaves inside this space?
Is it a valid method to get fast, acurate and predictive daylight calculation?

Anyway, I was frightened with plethora of variations and possibilities
to solve this problem.

thank you,

regards
Vangelis

> as Rob said, bringing the light source closer to the scene is a good
> start ;-) You can do this in your case by using the gensky modifier for
> your horizontal skylight's glazing, instead of defining a glass pane
> plus an outside sky dome (I assume that you do not have any visible
> geometry that is seen through the horizontal skylight). The second is
> that in your case, it may be possible to define an mkillum surface in
> the vertical clerestory windows. This would produce an uniform illum
> source accounting for the external blinds and certainly help a lot to
> improve rendering times with acceptable image quality.
>
> I would try to go with such a set-up. Replace the (vertical) clerestory
> glazing with a mkillum surface, the (horizontal) skylight glazing with
> the gensky modifier, and set higher ambient paramters as Rob suggested
> (and set a lower -ab, 2 or 3 should be fine with a good -av value!!!).
>
> In case this is not enough - one COULD try to introduce a second mkillum
> surface below the internal shades, as these probably also are a bit
> tricky to calculate. In this case, one would place a gensurf-generated
> surface just below the internal shades, with a resolution to account for
> variations in the structure (I would try something like 4x4 from what I
> see on the image), which will be invisible, but replace all ambient
> calculations on top of the internat shades by 4x4 illum sources. This
> would lead to a very simple scene, with very short rendering times and
> virtually no noise. BUT - first try the other options!
>